6 volt coils

I have been using the same Custom Chrome coils on the KH for years (the Chrome 6 volt), and the brackets get loose very fast so that the coil is just floating on the rivets after a while. Is there another supplier of a better 6 volt coil? The other thing I am wondering is that there should be some resistance between the two terminals on the coil? I have heard 1.5 to 3 Ohms, but when I put a tester on it that has been zeroed, it just jumps to zero. No resistance? Does this mean the coil is not working correctly?

Thanks,
Barry '55 KH